Refrigeration apparatus for inducing local anesthesia



Oct. 1947- J. s. RESTARSKI m- AL REFRIGERATION APPARATUS FOR INDUCING LOCAL A NESTHESIA Filed Oct. 30, 1844 2 Sheets-Sheet 1 gvwwvto ns siarski J. S. RESTARSKI ET AL REFRIGERATION APPARATUS FOR INDUCING LOCAL ANESTHESIA 2 Sheets-Shee t 2 Filed Oct. 30, 1944 gvwwwbbms JA. litesmm i "4 A.P;Blach m W Patented Oct. 21, 1947 REFRIGERATION APPARATUS FOR INDUC- ING LOCAL ANESTHESIA Joseph S. Restarski and Arthur P. Black,

United States Navy A Application October 30, 1944, Serial No. 561,142 1 Claim. (01. 128-400) (Granted under the act of March 3, 1883, as

This invention relates to a method and apparatus for inducing local anesthesia and has for an object to provide an improved method and apparatus for inducing anesthesia locally in any Part of the body and particularly for producing denta1 anesthesia.

A further object of this invention is to provide a method and. apparatus for providing a local anesthesia which, while it will be described in connection with dental anesthesia permitting oral operations, is also intended for use in connection With local anesthesia on various parts of the body, as the limbs, fingers, or other areas wherever a small operative area or portion of the body may be conveniently subjected to the anesthetic effect of local refrigeration.

A further object of this invention is to provide a method and apparatus for subjecting any area and particularly the dental area of the human body to local refrigeration close to the freezing point, thereby permitting the refrigerated operative area to be painlessly operated upon without shock to the patient or injury to any of the tissues from the refrigeration.

A further object of this invention is to provide a method and apparatus for gradually lowering the temperature to the refrigerating temperature which provides the anesthesia and thereafter gradually raising the temperature to the normal temperature, thereby eliminating any pain as a result of an abrupt change in temperature.

With the foregoing and other objects in View, the invention consists in the construction, combination and arrangement of parts hereinafter set forth, claimed and illustrated in the drawings in which:

Fig. 1 is a perspective view of the refrigeration applicators of this invention.

Fig. 2 is a top plan view of the applicators of this invention applied tothe external and internal gingival surfaces of the maxilla or the mandible.

Fig. 3 is a side View of Fig. 2.

Fig. 4 is a sectional view through one of the applicators.

Fi 5 is a top plan view of a slightly modified form of applicator and holder.

Fig. 6 is a sectional view of the applicator of Fig. 5, and

Fig. 7 is a partly sectional, partly elevational view of the refrigerant circulating apparatus of this invention.

There is shown at If) a refrigerant applicator of this invention which consists of a small enclosed vessel having entrance and exit ports ll amended April30, T928; 370 O. G. 757) and I2. The applicator will be shaped to conformto the portion or operative area of the. patient to which it is to be applied. The applicators herein shown are generally intended to be used as gingival applicators although the same applicators can obviously be used on a finger or other small area of the patient. When used as gingival applicators the applicator Ill as shown is substantially flat and has the entrance and exit ports I l and [2 located adjacent the upper edge thereof. These applicators It) may be made of a, semiflexible material such as thin sheet copper or silver or any other suitable semi-flexible metal or material having good heat conducting properties. Flexible tubings l3 and I4 are connected to the ports H and I2 for conducting a refrigerant to and from the applicator l0.

As shown in Figs. 2 and 3, a pair of applicators ID are used on the interior and exterior gingival surfaces, being held in such operative area by means of the holder l5. This holder l5 consists of a contractal spring portion I6 having dental embracing fingers l1 and flat spring extensions I 8 adapted to be pressed against the outer surfaces 20 of the gingival applicators ID. The fingers H are recessed as at 2| so as to permit the refrigerant tube M to connect the two applicators on the opposite sides of the gingival surfaces 22, the applicator holder fingers 2| being intended to grasp on the opposite sides of'a molar 23. As a result of such construction the holder l5 presses the inner surfaces 24 in firm contact with the gingival surfaces 22 whereby a refrigerant 28 circulating through the tubes l3 and applicators It by way of the connecting tube M will conduct heat away from the gingival surfaces 22.

In the form shown in Figs. 5 and 6 the applicator l 0' is provided with angularly extending ports II and I2, the port l2 being an extended neck as shown for cooperation with the applicator connecting tube [4, also the applicator holder I 5 is provided with dental embracing fingers H which are provided with apertures 2| through which the applicator port necks l2 extend for receiving the connecting tube I4.

The refrigerating unit for circulating a refrigerant through the applicators I0 is shown in Fig. '7. This refrigerating unit may consist of an outer chamber 25 adapted to receive a refrigerating mixture 26 of crushed ice and salt and an inner refrigerant chamber 21. The chamber 21 acts as a reservoir for the refrigerant 28, a preferred refrigerant consisting of about water and 35% ethyl alcohol. Extending through a stopper 30 on the chamber 21 is a tube 3| connecting to a circulating pump 32 whose outlet 33 is connected to a glass or copper coil 34. This coil 34 is wound about through the refrigerating mixture 26 within the outer chamber 25 and leads past a control valve 35 through a stopper 36 to the bottom .of a flask 31. Flask 31 is provided with an outlet port 38 near its top to which is connected a bulbular member 40, which in turn is connected to one of the applicator tubes l3.

The bulbular member 40 is provided with a chimney 4| through which is extended a thermometer 42, the thermometer 42 preferably fitting snugly into the chimney '41 to preventa-ny leakage therethrough. The refrigerant reaching the first applicator Ill goes through connecting tube M to the second applicator H1 in the direction shown by the various arrows thereon and thence returns by the second tubel3 to the second bulbular member 43 with its chimney 44 and thermometer 45 and through the stopper 30 back intothe refrigerant reservoir chamber 21'.

In. operation, the applicators lil are held in position on the gingival surfaces 22 adjacent the rootof the tooth to be operated upon as shown in Figs. 2 and They may be placed in position by means of the conventional rubber dam clamp forceps 46, it being observed that the holder I5 is similar to a conventional rubber dam clampexcept as modified herein to hold the applicators instead of a rubber: dam. The refrigerant 28 in the reservoir chamber 21 and coil tube 84 are at or close to the freezing temperature. The flask 3? is continuously exposed-to'room temperature andzthe refrigerant and-the applicators and tubes l3;will be at room temperature atthe commencement of the operation.

As pump 32 is operated, the. refrigerant will circulate in the direction of the arrows.,the refrigerant in the flask 3r! cooling gradually, thespeed with which it. is cooledrbeing determined both by the speed ofthepump 32 a-nd'the control valve 35; The operator will watch the first thermometer 42- so as. to controltthe lowering of: the temperature intherefrigerant passing through the applicators flLuntil it has reached the desired low tem-.- perature of aboutzero to. two. degrees; centigrade, that. is, justat or above. the freezing temperature. Bya suitable control-of the pump32- and of the valve 35; the temperature ofithe; refrigerant 2% leaving the flask Elmay be maintained atthe dc? sired'temperature. Aslow drop of temperature of the refrigerant Ziipassing through the applicaters til avoids any'pain in the gingival. tissues such as is often caused by any. sudden. changein temperature. The second thermometer 45' will reach a temperature of aboutonedegree. higher than the temperature indicated: on 'thefirstgthermometer Mgand will generally maintain this; one degree diiferential as. long as the. refrigerant is circulated:

After thegingival; tissues have beenthuscool-ed, itwill be found that local anesthesia; has? been-in"- duced and drilling or other operative procedure may be performed without pain to the patient, It has been found that it takes an average of four or five minutes to obtain effective anesthesia and thereafter that the temperature of zero to two degrees centigrade may be maintained safely with- .out any injury to any of the oral tissues for a sufficient time for drilling or other operative procedure to be carried out. It has been determined experimentally that no harm or injury is caused to any tissues maintained slightly above freezing up to four hours or more although an average of about tento twenty minutes is all that is usually needed in dental operations. After the drilling or operative procedure is completed, the pump 32 is stopped, discontinuing its circulation, but the gingival applicators ID are left in position for a while, however, until the refrigerant therein gradually warms up, as the gingival tissues gradually warm up to normal temperature, thus slowing up the return of the normal temperature and preventing any pain-causing sudden change in temperature; When the normal temperature is reached, the applicators are removed without leaving any after pains.

Other modifications and changes in the number and arrangement of the parts may be made by those skilled in the art without departing from the nature of this invention, within the scope of what is hereinafter claimed.

The invention herein described and claimed may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

In an apparatus for inducing dental anesthesia by local refrigeration, a gingiv-al applicator means comprising a pair of flattened hollow vessels of good thermal conductivity, refrigerant inlets and outlets atopposite ends of said vessels, and means for holding said vessels on the gingival tissues comprising a holder and flattened spring arms adapted to press said applicator vessels against the gingival tissues, said holder having tooth embracing fingers: for securing. said holder in position.

JOSEPH S. RESTARSKI. ARTHUR P. BLACK.

REFERENCES CITED The following references are of record in the file of this. patent;

UNITED STATES PATENTS Number Name Date 39,673 Oudry Aug. 25, 1863 902,016 C'opeman Mar. 21, 1933 787,920 Hofmann Apr. 25, 1905 1,011,606 Fulton Dec. 12, 1911 OTHER REFERENCES General Catalog of S. S. White Dental Mfg. 00., page 148, Clamp 206, 

